Interesting thread. Now the following thing that I am going to write is going to make more than one gunsmith cringe. It goes a bit against the stream of thought. I hope I will succeed in making my idea understood as English is not my mother tongue.
First , we all agree that a correctly sleeved action or a custom action properly machined would have the locking lugs of the bolt in contact with the lug abutment in the action in the cocked position. When the firing pin is released , I understand that there would be minimal parasite vibrations produced , and so because the top lug is not slaming against the top abutment and the rear of the bolt is not slaming against the bottom of the receiver , even when the 60000psi of thrust push on that bolt.
Now take a fatory receiver like the Remington 700, with its sloppy bolt .25wsm explained very well how the bolt get back into some sort of central position during the firing sequence. But I wonder if that can not create parasite vibration? A gunsmith who has tought me few things was blue printing his receivers in such a way that the indicating rod in the receiver would be centered on the front part of the action at the lug levels, but loose enough that it could be slanted up to the inside of the rear bridge. The diameter of that rod on most of its diameter would be an exact Match of the bolt body, only the part under the lug area being a close match to the receiver. The indicating rod can be held in the upward position with a shim between its body and the inside bottom of the rear part of the receiver while it's getting indicated into a trueing jig. The receiver is then conventionaly single point blue printed.The bolt face and lugs of the bolt are trued in a conventional way to be perpendicular to the bolt body. So you can imagine that by doing so , the rear of the bolt stays in the upward position at all time during the firing sequence and the bolt lugs are always in contact with the receiver lugs.Also another thing which I have never seen mentioned, is that the cartridges in the magazine below are also exercising an upward pressure on the bolt at all time ( except when you are on your last round), of course not a great pressure ( we can push the rounds down with our thumb after all) and not as great as the upward pressure created by the cocked firing pin. The bolt remains very fluid to open and close . The only disadvantage I can see with that method is that you would lose a few moa of elevation as the barrel is starting to point downward . Not really a problem with the options of slanted rails available on the market. Now I am not saying that this is the right way to do things, but it has certainly worked for the gunsmith who told me that trick and his customers. I have blue printed and rebarreled a few rifles like that and I have not had any issues with function or accuracy. I can not tell if the rifles I have done that way would have shot better or worse than going a more conventional way. I would be happy from the experts on the forum about their thoughts on this . Thanks .
